Jack



FIG. 1 is a perspective of a jack embodying our new design;

FIG. 2 is a right side elevation thereof;

FIG. 3 is a front elevation thereof;

FIG. 4 is a left side elevation thereof;

FIG. 5 is a rear elevation thereof;

FIG. 6 is a top plan thereof; and,

FIG. 7 is a bottom plan thereof.

The ornamental design for jack, as shown. 